Alert archive / North Dakota / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 241, NWS Grand Forks, ND

August 23, 2002Cavalier County, Ramsey County, North Dakota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 23, 2002, 6:32 PM CDT for Cavalier County, Ramsey County, North Dakota. It was in force for 43 min. 3 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Aug 23, 2002, 6:32 PM CDT (23:32 UTC)
Expired
Aug 23, 2002, 7:15 PM CDT
In force
43 min
Issued by
NWS Grand Forks, ND
Area
Counties, with a storm outline in the text

Counties Cavalier County, ND, Ramsey County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 145 km from the middle of the area, began a volume at 23:34 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Aug 23, 6:40 PM CDTHail 0.75Alsen, ND
Aug 23, 6:50 PM CDTHail 0.75Edmore, ND
Aug 23, 7:20 PM CDTTornado F0Lawton, NDThis tornado crossed into Walsh county.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 12:00Z, 11.5 hours before the alert went out and 251 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Bismarck Municip, ND at 12:00Z on 2002-08-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Bismarck Municip, ND at 12:00Z on 2002-08-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
855 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
306 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Grand Forks, ND wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 23, 1:09 PM CDT, 5 hours 23 minutes earlier.

Area forecast discussion, Aug 23, 1:09 PM CDT, 5 hours 23 minutes before
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
109 PM CDT FRI AUG 23 2002

...FORECAST CHALLENGE WILL BE PRECIPITATION CHANCES OVERNIGHT...

.CURRENT OBSERVATIONS...
WEAK SURFACE FRONT LOCATED WELL NORTH OF THE BORDER AND IS SLOWLY
MOVING SOUTH. SHORT WAVE EVIDENT ON WATER VAPOR IMAGERY ALONG AND
AHEAD OF FRONT. A FEW LIGHTNING STRIKES HAVE BEEN NOTED ALONG FRONT.
DEWPOINTS ACROSS AREA REMAIN IN THE MID 60S WITH ALL MODELS
UNDERDOING THE LOW LEVEL MOISTURE.

.SHORT TERM...
MAIN CHALLENGE IS THUNDER OVERNIGHT. SOME LOW LEVEL MOISTURE PRESENT
BUT LIMITED ABOVE THIS LAYER. SOME WEAK SURFACE/850MB CONVERGENCE
AND INSTABILITY TONIGHT. WILL PUT ISOLATED MENTION ACROSS MUCH OF
THE FORECAST AREA(FA) WITH SLIGHTLY HIGHER POPS ACROSS NORTHWEST
MINNESOTA.

.MID TERM...
WEAK SURFACE HIGH WILL PUSH FRONT SOUTH OF FA ON SATURDAY AND WILL
KEEP PRECIPITATION OUT OF THE REGION UNTIL SUNDAY NIGHT. BY SUNDAY
NIGHT...UPPER LEVEL LOW EJECTS OUT OF THE PACIFIC NORTHWEST AND INTO
THE NORTHERN HIGH PLAINS. SEVERAL WAVES EXPECTED TO ROTATE AROUND
SYSTEM AND WILL BRING CHANCE OF THUNDERSTORMS TO THE RED RIVER
VALLEY AND AREAS WEST INTO MONDAY...HOWEVER MOISTURE WILL BE LIMITED
WITH A BLOCKING PATTERN TO THE SOUTH.

.EXTENDED FORECAST...
ECMWF IS ODD MODEL OUT IS SHOWING AMPLIFYING UPR LOW AND COLD AIR
DROPPING SOUTHEAST TOWARD NRN MN BY 12Z THU.  NCEP
ENSEMBLES/NOGAPS/MRF/CANADIAN ALL GO AGAINST THIS SHOWING MAIN POLAR
JET AND COLD AIR WELL NORTH ACROSS NRN CANADA WITH MUCH WEAKER 50H
SYSTEMS DROPPING THRU NRN PLAINS TUE-WED TIME FRAME.  CANADIAN AND
NOGAPS ARE EVEN WEAKER THAN THE MRF AND WOULD IMPLY ONLY SMALL
CHANCES OF PCPN TUE-WED VERSUS HEAVIER QPF OF MRF.  BELIEVE THIS MAY
BE RIGHT.  WILL HOWEVER STILL KEEP CHC IN PER CURRENT EXTENDED FOR
TUE-WED...THEN DRY THU-FRI AND STILL MILD WITH NEAR NORMAL TEMPS.

.FGF...NONE
DONAVON/RIDDLE

In the hours before

Special weather statement, Aug 23, 3:50 PM CDT, 2 hours 42 minutes before
MNZ001>009-013>017-022>024-027>031-040-NDZ006>008-014>016-024-
026>030-038-039-049-052>054-232345-

SPECIAL WEATHER STATEMENT
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
350 PM CDT FRI AUG 23 2002

...ISOLATED SEVERE THUNDERSTORMS POSSIBLE TONIGHT ACROSS NORTHEAST
NORTH DAKOTA AND ADJACENT NORTHWEST MINNESOTA...

SYNOPSIS...
SCATTERED THUNDERSTORMS ARE EXPECTED TONIGHT ACROSS EASTERN NORTH
DAKOTA...NORTHWEST AND WEST CENTRAL MINNESOTA. A WEAK COLD FRONT
WILL MOVE FROM NORTH TO SOUTH ACROSS THE REGION OVERNIGHT. MOISTURE
ASSOCIATED ALONG THE FRONT COUPLED WITH LIFT FROM AN UPPER LEVEL
DISTURBANCE WILL ENHANCE THUNDERSTORM ACTIVITY THIS EVENING ALONG
THE INTERNATIONAL BORDER...AS THE THUNDERSTORMS MOVE INTO THE AREA
AFTER 5 PM.

AREA OF CONCERN...
NORTHEAST NORTH DAKOTA AND ADJACENT PORTIONS OF NORTHWEST MINNESOTA.

TIME...
5 PM UNTIL 10 PM.

TYPE OF HAZARD...
LARGE HAIL WILL BE THE MAIN THREAT.

KELLENBENZ

NNNN
Local storm report, Aug 23, 6:19 PM CDT, 13 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS, ND
619 PM CDT FRI AUG 23 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0525 PM    3 N SARLES                ND   .75 INCH HAIL
08/23/02   CAVALIER                       REPORTED BY PUBLIC.

0530 PM    7 SW WALHALLA             ND   .75 INCH HAIL
08/23/02   PEMBINA                        REPORTED BY CO-OP OBSERVER.

0545 PM    13 W CAVALIER             ND   .88 INCH HAIL
08/23/02   PEMBINA                        REPORTED BY CO-OP OBSERVER.

0555 PM    1 N PERTH                 ND   1.00 INCH HAIL
08/23/02   TOWNER                         REPORTED BY CO-OP OBSERVER.

DPORTER
Local storm report, Aug 23, 6:30 PM CDT, 2 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS, ND
630 PM CDT FRI AUG 23 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0628 PM    2 E MOUNTAIN              ND   1.00 INCH HAIL
08/23/02   PEMBINA

JH
Local storm report, Aug 23, 6:32 PM CDT, 0 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND FORKS, ND
632 PM CDT FRI AUG 23 2002

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0620 PM    5 NW BISBEE               ND   .75 INCH HAIL
08/23/02   TOWNER                         REPORTED BY CO-OP OBSERVER.

0630 PM    3 S MOUNTAIN              ND   TORNADO
08/23/02   PEMBINA                        REPORTED BY CO-OP OBSERVER.

DPORTER

The office that day

Everything else NWS Grand Forks, ND issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 23, 4:52 PM CDTSevere Thunderstorm WarningFGFTowner38 min
Aug 23, 5:07 PM CDTSevere Thunderstorm WarningFGFCavalier38 min
Aug 23, 5:30 PM CDTSevere Thunderstorm WarningFGFTowner45 min
Aug 23, 5:42 PM CDTSevere Thunderstorm WarningFGFCavalier48 min
Aug 23, 5:44 PM CDTSevere Thunderstorm WarningFGFPembina46 min
Aug 23, 6:13 PM CDTSevere Thunderstorm WarningFGFTowner47 min
Aug 23, 6:20 PM CDTTornado WarningFGFPembina40 min
Aug 23, 6:43 PM CDTSevere Thunderstorm WarningFGFWalsh47 min

Nearby

Severe Thunderstorm Warnings in North Dakota, 2002Every severe thunderstorm warning in 2002

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.